KR102173116B1 - Light emitting module, and backlight unit - Google Patents

Abstract

The embodiment includes a light-emitting element and a light guide member that receives light irradiated from the light-emitting element, reflects the received light, and emits the reflected light, wherein the light guide portion is a guide body, the An incident part located on one side of the guide body and receiving light from the light emitting element, a reflecting part located in the guide body and having a reflective surface for reflecting light received by the incident part, and light reflected by the reflective surface And an emission part that emits, and a distance from the emission part to the reflective surface decreases as the distance from the incidence part increases.

Description

A light emitting module, and a backlight unit {LIGHT EMITTING MODULE, AND BACKLIGHT UNIT}

The embodiment relates to a light emitting module and a backlight unit.

A liquid crystal display device that is a light-receiving element without its own light source requires a separate light source device that can illuminate the entire screen from the rear. Such a lighting device for a liquid crystal display is generally referred to as a back light unit.

In general, the backlight unit may be classified into an edge-light method and a direct lighting method according to a method in which a light source (eg, LED) is arranged.

In the edge-light method, a light source (eg, LED) may be disposed on the side of the light guide plate to guide light. The edge-light method can be applied to a relatively small liquid crystal display device such as a desktop computer or a notebook monitor, and has good light uniformity and excellent durability.

In the direct method, a light source is arranged under the liquid crystal panel to directly illuminate the front surface of the liquid crystal panel, and this direct method may be used for a medium-large display device of 20 inches or more.

In general, a backlight unit includes a light emitting module including light emitting diodes (LEDs) mounted on a bar-shaped circuit board, a light guide plate (LGP), a reflector sheet, and It may include an optical sheet (Optical Sheet).

The embodiment provides a light emitting module and a backlight unit capable of reducing power consumption and heat generation and providing uniform luminance and uniform color.

The light emitting module according to the embodiment includes a light emitting device; And a light guide member configured to receive light irradiated from the light emitting device, reflect the received light, and emit the reflected light, wherein the light guide unit includes a guide body; An incident part located on one side of the guide body and receiving light from the light emitting element; A reflective unit located within the guide body and having a reflective surface for reflecting light received by the incident unit; And an emission unit that emits light reflected by the reflection surface, and a distance from the emission unit to the reflection surface decreases as the distance from the incident unit increases.

The guide body may include an upper surface, a lower surface facing the upper surface, and side surfaces positioned between the upper surface and the lower surface, and the entrance part is located on one side of the guide body, and the exit part It may be located on the other side of the guide body.

The incidence portion may be an opening formed on one side of the guide body.

The exit portion may include a plurality of openings formed to be spaced apart from each other on the other side of the guide body.

One end of the reflective surface may contact the inside of the first edge of the guide body, the other end of the reflective surface may contact the inside of the second edge of the guide body, and the first edge and the second edge Corners can face each other.

A distance from the reflective surface may be smaller as the plurality of openings are located further from the incident part.

The inside of the guide body is empty and may be filled with air.

The reflective surface is flat, and an angle formed between the reflective surface and the incident part may be an acute angle.

The backlight unit according to the embodiment includes a light emitting module that irradiates light; A light guide plate guiding light irradiated from the light emitting module; And an optical sheet disposed on the light guide plate and diffusing light emitted from the light guide plate, and the light emitting module may be an embodiment.

The emission unit may include a plurality of openings spaced apart from each other, and a distance from the reflective surface may be smaller as the plurality of openings are located farther from the incidence unit.

The light guide plate has a light incident surface on which light irradiated from the light emitting module is incident, and a light scattering pattern may be formed on the light incident surface to correspond to each of the plurality of openings.

The embodiment can reduce power consumption and heat generation, and provide uniform brightness and uniform color.

1 illustrates a display device including a backlight unit according to an embodiment.
2 is an exploded perspective view of the light emitting module illustrated in FIG. 1.
3 is a perspective view illustrating a combination of the light emitting module shown in FIG. 2.
4 shows a plan view of the light emitting module shown in FIG. 2.
5 shows a front view of the light emitting module shown in FIG. 2.
6 shows light incident on the light incident surface of the light guide plate shown in FIG. 2.

Hereinafter, embodiments will be clearly revealed through the accompanying drawings and descriptions of the embodiments. In the description of the embodiment, each layer (film), region, pattern, or structure is "on" or "under" of the substrate, each layer (film), region, pad or patterns. In the case of being described as being formed in, "on" and "under" include both "directly" or "indirectly" formed do. In addition, the standards for the top/top or bottom/bottom of each layer will be described based on the drawings.

In the drawings, the sizes are exaggerated, omitted, or schematically illustrated for convenience and clarity of description. Also, the size of each component does not fully reflect the actual size. Also, the same reference numerals denote the same elements throughout the description of the drawings. Hereinafter, a light emitting module and a backlight unit according to an embodiment will be described with reference to the accompanying drawings.

1 illustrates a display device 100 including a backlight unit 120 according to an exemplary embodiment.

Referring to FIG. 1, the display apparatus 100 includes a cover 110, a back light unit 120, a liquid crystal panel 130, and a light blocking tape 140.

The cover 110 accommodates and fixes the backlight unit 220 and the liquid crystal panel 230.

The backlight unit 120 may be disposed inside the cover 110, and may generate light to emit light to the liquid crystal panel 130. For example, the backlight unit 120 may be an edge-light type in which light is irradiated to at least one side of the light guide plate 123 (hereinafter referred to as “light-incident surface”).

The backlight unit 120 includes a light emitting module 121, a light guide plate 123, a reflector sheet 124, and an optical sheet 125.

The light-emitting module 121 may be located adjacent to the light-incident surface 101 that is one side of the light guide plate 123, and may emit light to the light-incident surface 101 of the light guide plate 123.

The light emitting module 121 may include a substrate 161, a light emitting device 165, and a light guide part 167.

The substrate 161 may be a printed circuit board, for example, a flexible printed circuit board (PCB).

A circuit pattern including a first conductive layer 212 and a second conductive layer 214 may be formed on the substrate 161. First power (eg, positive (+) power) may be supplied to the first conductive layer 212, and second power (eg, negative (-) power) may be supplied to the second conductive layer 212. I can.

The light emitting device 165 is mounted on the substrate 161 and may generate light. For example, it may be disposed on the substrate 161 to be electrically connected to the first conductive layer 212 and the second conductive layer 214.

The light emitting device 165 may be a light emitting diode (LED), and may be in the form of a chip or a light emitting device package. For example, the light emitting device 165 may be a side view type light emitting device package.

The number of light emitting devices 165 mounted on the substrate 161 may be one or more. For example, in order to minimize the number of light-emitting elements 165, one light-emitting element 165 may be mounted on the substrate 161.

The light guide unit 167 guides or reflects the light irradiated from the light emitting element 165 to the light incident surface 101 of the light guide plate 123.

FIG. 2 is an exploded perspective view of the light emitting module 121 shown in FIG. 1, FIG. 3 is a combined perspective view of the light emitting module 121 shown in FIG. 2, and FIG. 4 is a light emitting module 121 shown in FIG. ) Shows a top view, and FIG. 5 shows a front view of the light emitting module 121 shown in FIG. 2.

2 to 5, the light emitting module 121 guides the light emitting device 165 mounted on the substrate 161 and the light irradiated from the light emitting device to the light incident surface 101 of the light guide plate 123. It may include a light guide unit 167.

The light guide part 167 includes a guide body 310, an incidence part 312 located on one side of the guide body 310, an output part 314 located on the other side of the guide body 310, and a body It is located within 310 and may include a reflective unit 316 for reflecting or guiding the light incident through the incident unit 312 to the emission unit 314.

The rest of the guide body 310 except for the incident portion 312 and the exit portion 314 may be made of a non-transmissive material.

As shown in FIG. 2, the guide body 310 may have a rectangular parallelepiped shape, but is not limited thereto, and may be in various forms according to the shape of the light guide plate 123 or the shape of the light incident surface 101 of the light guide plate 123. Can be implemented.

For example, the guide body 310 has an upper surface 401, a lower surface 402 facing the upper surface 401, and side surfaces 403a and 403b positioned between the upper surface 401 and the lower surface 402 ,403c,403d).

The inside of the guide body 310 may be empty, filled with air, or may be in a vacuum state.

The incidence part 312 may be located on one side 403b of the guide body 310, and light irradiated from the light emitting element 165 may be incident to the inside of the guide body 310.

The incident part 312 may be in the form of an opening formed on one side surface 403b of the guide body 310 or may be in the form of a window made of a light-transmitting material.

The shape of the incident part 312 may match the shape of the light emitting surface of the light emitting device 165, and the area of the incident part 312 may be equal to or greater than the area of the light emitting surface of the light emitting device 165.

For example, the incident part 312 may correspond to one light emitting element 165.

The light emitting surface of the light emitting element 165 may face the incident part 312, and the light irradiated from the light emitting surface of the light emitting device 165 passes through the incident part 312 and is irradiated into the guide body 310. I can.

The emission part 314 may be located on the other side 403c of the guide body 310 and may emit light out of the guide body 310.

The angle formed by the incident unit 312 and the emission unit 314 may be vertical, but is not limited thereto. The emission part 314 may face the light incident surface 101 of the light guide plate 123.

The emission part 314 may be in the form of an opening formed in the other side 403c of the guide body 310 or may be in the form of a window made of a light-transmitting material.

For example, the exit portion 314 may include a plurality of openings (openings, 314-1 to 314-n, n>1 natural number) formed to be spaced apart from each other on the other side 403c of the guide body 310 I can.

The scattering patterns 111-1 to 111-n and a natural number n>1 for scattering the irradiated light may be formed to be spaced apart from the light incident surface 101 of the light guide plate 123.

Each of the plurality of openings 314-1 to 314-n, a natural number of n>1) includes light scattering patterns 111-1 to 111-n, n>1 formed on the light incident surface 101 of the light guide plate 123 Is a natural number).

The area of each of the plurality of openings 314-1 to 314-n, n>1 natural number) may be equal to or greater than the area in which the corresponding scattering pattern (111- to 111-n, n>1 natural number) is formed. have.

In addition, the shape of each of the plurality of openings 314-1 to 314-n, n>1 natural number) may be implemented in various shapes such as a polygon, a circle, and an oval.

The shape of the exit portion 314 formed on the other side 403c of the guide body 310 is not limited to the above-described bar. For example, the exit part 314 may be one opening formed in the other side surface 403c of the guide body 310.

The reflective part 316 may be disposed inside the guide body 310, and may have a flat reflective surface 316-1 for reflecting light irradiated from the light emitting element 165 to the emission part 314.

The angle θ formed between the reflective surface 316 and the incident part 312 may be an acute angle greater than 0° and less than 90° (0°<θ<90°).

One end of the reflective surface 316 may be in contact with the inner side of the first edge 411 of the guide body 310, and the other end of the reflective surface 316 is of the second edge 412 of the guide body 310 It may be in contact with the inside, and the first and second corners 411 and 412 may face each other. In addition, the upper end of the reflective surface 316 may contact the inner upper surface of the guide body 310, and the lower end of the reflective surface 316 may contact the inner lower surface of the guide body 310.

The distance (d, see FIG. 4) from the emission part 314 to the reflective surface 316-1 may decrease as the distance from the incident part 312 or the light-emitting element 165 increases.

The distance d between the opening and the reflective surface 316 may be smaller as the opening is located farther from the incident part 312 or the light emitting element 165.

The distance between any one of the plurality of openings 314-1 to 314-n, a natural number of n>1 (for example, 314-5) and the reflective surface 316-1 is the plurality of openings 314-1 To 314-n, a natural number of n>1) may be smaller than the separation distance between the other opening (eg, 314-4) and the reflective surface 316-1, and any one opening (eg, 314- The separation distance between 5) and the incidence unit 132 may be greater than a separation distance between the other opening 314-4 and the incidence unit 132.

The distance d between the opening and the reflective surface 316 is made smaller as the opening is located farther from the incident part 132, so that the amount of light emitted from each of the openings may be uniform.

6 shows light incident on the light-incident surface 101 of the light guide plate 123 in FIG. 2.

Referring to FIG. 6, since the distance d between the opening and the reflective surface 316 is smaller as the opening located farther from the incident part 132 or the light emitting element 165, the amount of light emitted through each of the openings Can be uniform throughout.

Since light having a uniform amount of light can be irradiated on the entire surface of the light-incident surface 101 of the light guide plate 123, the embodiment can provide uniform luminance and uniform color.

As shown in FIG. 4, the reflective part 316 may be implemented to fill a part of the inside of the guide body 310, but is not limited thereto.

For example, in another embodiment, the reflective part 316 may have only a reflective surface in the form of a plate or a sheet.

The reflector 316 may be made of the same material as the guide body 310, but is not limited thereto. For example, the reflective part 316 may be made of a reflective material, such as white silicon. Alternatively, the reflective part 316 may be made of a light-transmitting material, and may include a reflective member coated on the reflective surface 316-1.

The light guide plate 123 is disposed so that the light incidence surface 101 faces the emission portion 314 of the guide body 310, receives light emitted from the emission portion 314 and guides it toward the liquid crystal panel 130.

For example, the light guide plate 123 may be formed of polymethylmethacrylate (PMMA), polycarbonate (PC), or polyethylene (PE).

The reflective sheet 124 is disposed on the rear surface (or lower surface) of the light guide plate 123, and reflects the light emitted to the rear surface of the light guide plate 123 to re-enter the light guide plate 123.

The reflective sheet 124 may be formed of a material that has high reflectivity and can be used in an ultra-thin type, and may use polyethylene terephtalate (PET).

The optical sheet 125 is disposed on the front surface (or upper surface) of the light guide plate 123 and diffuses light emitted from the light guide plate 123 at a predetermined angle. For example, the optical sheet 125 may uniformly irradiate light guided by the light guide plate 123 to the liquid crystal panel 130.

The optical sheet 125 may have a structure in which a plurality of optical sheets (eg, a protective sheet, a prism sheet, and a diffusion sheet) are stacked, or a structure including a plurality of optical sheets and a micro lens array.

The liquid crystal panel 130 is provided on the entire surface of the optical sheet 125.

The liquid crystal panel 130 is in a state in which a liquid crystal is placed between the glass substrates and a polarizing plate is placed on both glass substrates in order to utilize the polarization of light. Here, the liquid crystal has an intermediate characteristic between a liquid and a solid, and the liquid crystal, which is an organic molecule having fluidity like a liquid, has a state that is regularly arranged like a crystal, and the molecular arrangement is changed by an external electric field. Display an image. A color filter (not shown) may be provided on the front surface of the liquid crystal panel 230.

The light shielding tape 140 may be composed of a double-sided black tape, and is attached between the liquid crystal panel 130 and the cover 110 to block light leaking through the gap between the liquid crystal panel 130 and the cover 110. .

Compared to a backlight using a plurality of light-emitting elements, since the embodiment supplies light to the light guide plate 123 using one light-emitting element, it is possible to reduce heat generation and power consumption.

In addition, according to the embodiment, light having a uniform amount of light may be irradiated on the entire surface of the light-incident surface 101 of the light guide plate 123, and uniform brightness and uniform color may be provided.

Features, structures, effects, and the like described in the embodiments above are included in at least one embodiment of the present invention, and are not necessarily limited to only one embodiment. Furthermore, the features, structures, effects, etc. illustrated in each embodiment may be combined or modified for other embodiments by a person having ordinary knowledge in the field to which the embodiments belong. Accordingly, contents related to such combinations and modifications should be interpreted as being included in the scope of the present invention.

110: cover 121: light-emitting module
123: light guide plate 124: reflective sheet
125: optical sheet 120: backlight unit
130: liquid crystal panel 140: shading tape
161: substrate 165: light emitting element
167: light guide part 310: guide body
312: entrance section 314: exit section
316: reflector.

Claims (11)

Light-emitting elements; And
And a light guide member configured to receive light irradiated from the light emitting device, reflect the received light, and emit the reflected light,
The light guide part,
A top surface, a bottom surface facing the upper surface, and a side surface positioned between the upper surface and the lower surface, wherein the side surface is a first side, a second side opposite to the first side, and a first A guide body that connects the side and the second side and includes a third side and a fourth side that are opposite to each other;
An incident part positioned on a first side surface of the guide body and receiving light from the light emitting element;
A reflective unit located in the guide body and having a reflective surface reflecting light received by the incident unit; And
It is located on the third side of the guide body, and includes an emission unit for emitting light reflected by the reflective surface,
One end of the reflective surface is in contact with the inner side of the first corner where the first side and the fourth side of the guide body meet, and the other end of the reflective surface is a second side where the second side and the third side of the guide body meet. In contact with the inner side of the corner, and the first corner and the second corner face each other,
The entrance portion is an opening formed on one side of the guide body,
The exit portion includes a plurality of openings formed to be spaced apart from each other on a third side surface of the guide body,
A light-emitting module in which a separation distance from the reflective surface decreases as the plurality of openings of the emission part are located farther from the incidence part. delete delete delete The method of claim 1,
The upper end of the reflective surface is in contact with the inner side of the upper surface of the guide body, and the lower end of the reflective surface is in contact with the inner side of the lower surface of the guide body. delete The method of claim 1,
The angle formed by the first side and the third side of the guide body is vertical,
The reflective surface is flat, and the angle formed by the reflective surface and the incident part is an acute angle,
A light emitting module in which the inside of the guide body is empty and filled with air. delete The light emitting module according to any one of claims 1, 5, and 7;
A light guide plate guiding light irradiated from the light emitting module; And
A backlight unit disposed on the light guide plate and including an optical sheet for diffusing light emitted from the light guide plate. delete delete

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